Boiler plug expander



Aug. 8, 1933. E. DucHEsNE 1,921,810

' BOILER PLUG EXPANDER Filed Dec. 12, 1931 INVENTOR .'E/nes TDuchesneil' l i n ORNEY Patented Aug. 8, 1933 UNITED STATES PATENT OFFICE 'e 'Ihepresent invention relates to tools, and particularly to' an improvedtool or device for expanding hollow plugs in openings formed 1in boilershells and like apparatus. 1

Due to the limited amount of space available within such plugs,it hasbeen necessary to employ roller pins with much greater tapers than thoseapplied to expanders under ordinary conditions. Such -tapers of the pinsnecessarily require the rollers of the expander device to becorrespondingly tapered. In the useof such devices, however, muchdiflicultyhas been experienced in 4properly feeding the pin so as tocomplete the expansion operation with a minimum amount of rolling, inorder to prevent undesirable iiaking of the metal inside of theplug.

The object of the present invention is to provide a ydevice of thecharacter aforedescribed, wherein a novel pin and feed arrangementl isemployed, which will eiectively expand the plug `with the maximumrapidity, that is to say, with a minimum amount `of rolling, practicallyeliminating undesirable aking.

' The invention is illustrated in the accompanying drawing, wherein,Figure 1 is a longitudinal `central sectional view of an expander deviceembodying the present invention, shown applied to a plugv fitted into anopening in a portion fof a boiler; Fig. 2 is a side View,l onan-enlarged scale, vof the housing part of thedevice; Fig. 3 isv atransverse;` sectional view Vtaken on Athel line III-III of Figs-2; Fig.4 is an, enlarged side elevation of the roller pin of the device;` Fig.5 is an enlarged transverse `sectional view, taken D on the line V-V ofFig. 4; and Fig. 6 isan enlarged side elevation of one of the rollers ofth device.

Referring in detailto the drawing, a part ofV and is shaped to providec'am surfaces 9, l0 and` 11 so that each third of its circumference willhave a .005 cam effect against its respective roller, hereinafter to bedescribed. The rearrend 12 of thepin is squared, to engagea motor` orother driving member (not shown) of any of the well known designs forrotating the pin.

Vopening'the rollersrmay jbe inserted or removed 'for assembly or repairof the device.

lhousing provides a ledge 24, and a spacing ring A cylindrical sleevemember or housing vindicated generally by the numeral 13 is provided,

and comprises an enlarged hollow portion` 14 which yis internallythreaded for a part of its length at 15', for a `vpurposerhereinaftertobe described- The housing has a central portion 16, anda longitudinalpassageway 1-7, circular in cross section, passes through thecentral'portion land the forward endof the portion 14, the passagewaybeing of a slightlylarger diameter than .65 the diameterof the portion'lof theY pin. The housing also comprises a 'hollow end portion 184extending from the central portion 16. The por- Y tion 18 is providedwith longitudinal openings 19,

2'0 and 21 symmetrically formed in its sides and70 outwardlyconverging'toward the surfaceof said portion providing cages or socketsfor rollers 22. One of the facesof each-of they openings'is at an angletothe axis of thehousin'g. The rollers Iare tapered to correspond withthe taper ofthe end 8 ofthe roller pin,v and fit looselywithin the samebecause of the restricted distance` between theirfaces at Vthe outersurface ofthe end `portion 18. An opening 23 is formed in the outer endof the portion 18 of the housing through' which The pin is Si adapted toextendthrough the housing, its collar 6 being of a slightly lessdiameter than v the "interior of `the hollowportion 14 of the housing.When the pinis so insertedwithinrthe housing,

its collar is disposed within the said hollow portion 14 and its taperedend may extend Afor a limited distanceV through the openingy 23. The

and the interior of the hollow portion 14 of the 25 is disposed withinthe hollow portion 14 adjacent the ledge 24. The" central opening ofthering is in alignment with the passageway 1'7` and is of a diameterslightly greater than thediameter of the cylindrical portion 7 of thepin. MThe spacing ring acts as a stop against vwhich the collar 6strikes, limiting. the outwardl movement "of theroller pin. y A feed oradjusting; nut 26 is provided with an externally threaded surface 27,and the nut is screwed `into the hollow portion 14, its threaded surfaceengaging the threading at 15 in the hollow portion 14. Ari enlargedknurled head 28 isv formed onthe outer end rof the nut anda central bore29 is formed longitudi- -f nally through the nut,the` bore being ofafdin ledge 31.

ameter slightly greater than the diameter of the central portion 5 ofthe pin. The pin extends through the bore 29 with its squared end 12 atthe rear of the head 28. A part 30 of the body portion of the nut ishollowed out, the interior of the hollow portion being of a diametergreater than that of the bore 29, thereby providing a A spring 32 isdisposed around the central portion 5 of the roller pin, and one end ofsaid spring extends into the hollow portion 30 of the nut resting uponthe ledge 31. A discshaped seat 33 having a central opening 34 formedtherein to permit the passage of the pin therethrough, is disposedwithin the hollow portion 14 of the housing adjacent the forward end ofthe spring, providing a seat for said end of the spring. Circularchannels 35 and 36 are formed in the opposing faces of the seat 33, andthe pin collar 6, respectively, and ball bearings 37 are disposedbetween the seat and collar in the saidV channels, so that the rollerpin may be freely rotated while receiving thrust from the spring.

The end portion 18 of the housing being of a reduced diameter Withrelation to the central portionl, a'ledge 38 is provided. An annularspacing seat 39, having a centralopening 40, is disposed around the endportion 18 of the housving. The opening is of an enlarged diameter at 41so that when the inner end 42 of the seat bears against the outersurface of the boiler 1, around the outside of the opening 2, the.projecting end of the plug 3 may extend into said enlarged portion at41. The end 18 of the housing member is passed through the opening 40and the housing bears at its ledge 38, against the outer end 43 of theseat, and the housing isthereby held in a fixed spaced position withrelation to the boiler and the plug, as shown in Fig.r 1.

In operation, the device is positioned adjacent the boiler, as shown inFig. 1, with the spacing seat 39 over the end of the plug 3, and thehousing as aforesaid extending through the opening 40 and bearing on thespacing seat. When the nut 26 is unscrewed, as shown in Fig. 1, engagingonly a few of the threads .of the housing, the spring is not undertension and exerts no pressure upon the seat 33. The pin therefore isnot forced out against the rollers and the rollers are permittedA to'recede below the surface ofthe Yportion 18 of the housing soY that thehousing may be inserted Within the plug y3 without interference from therollers. The spring nut may be adjusted by screwing the same inwardly oroutwardly to provide the required tension of the springen the seat 33 soas to force the collar and pin forward, the latter against the rollers.The tapered cam surfaces yof the vpin will engage the rollers 22,forcing the same out- `wardly in their respective sockets 19, 20 and 21.

The spring will thus afford the pin a steady selffeeding action, andwhen the pin is rotated, the

camr surfaces will cooperate in the transmission `through the tendencyof the rollers to feed deeper into the plug, by reason of the effect ofthe slightfangles of the facesof the roller sockets 19,'20 and 21,aforedescribed.

While there has been hereinbefore described a specific embodiment of thepresent invention, it Will be apparent to those skilled in the art, thatmany and various changes and modifications may be made Without departingfrom the spirit of the invention, and it will be understood that all andany such changes and modifications as fall Within the scope of theappended claims are contemplated as a part of the present invention. i

The invention claimed and desired to be secured by Letters Patent is:v

1. A tool for expanding acylindrical object, comprising an expandermember free for lateral movement; a member forforcing said expandermember laterally to effect expanding of said object, said forcing memberhaving a surface having a cam effect circumferentially of the forcingmember and also a cam effect axially of the forcing member; means forrotating said forcing member to bring said circumferential cam effectinto play; and means for feeding the forcing member axiallyto bringVsaid axial cam effect into play. v

2. A tool for expanding a ,Cylindricalobject comprising an expandermember free for lateral movement; a memberl for forcing said expandermember laterally to effect expanding of said oblect, said forcing memberhaving a surface having a cam effect circumferentially of the forcingmember and also a cam' effect axially of the vforcingv member;A meansfor rotating said forcing member to bring said circumferential cameffect into play; andV means for feeding the forcf opposite said firstmentioned end; means at the outer end of 'said threaded memberforturning the threaded member into the housing; a chamber disposed inthe opposite'end of said threaded member; a seat secured to said forcingmeans;

`and aspring disposed in said housing and said chamber, having one ofitsr ends abutting said seat, and its opposite end abutting the outerend of said chamber, wherebyy the forcing means may be advanced towardthe expanding member b y lthe resilient pressure ofthe spring When thethreaded member is advanced.

4. A tool for expanding a cylindrical object comprising an expandermemberfree for lateral outward movement for expanding said object; amember rotatable and axially advanceable for forcing said yexpandermember laterally outward, Said forcing member being provided with asurface having a cam effect axially of the forcing member operableduring axial advancement thereof, and also having a cam effectcircumferentially of the forcing member operableduring a part of eachrotation thereof; means for rotating said forcing member; and means foraxially advancing said forcing member, said rotating means being capableof operation simultaneously with said advancing means, Vwhereby saidforcing member will axially advance previous to each saidpartrotationthereof to there.-

member threaded into the end of the housing '120 by successively bringaxial and circumferential cam eiects into play. v

5. A tool for expanding -a cylindrical object Y comprising an expander,member free for lateral during a part of each rotation thereof; meansfor rotating said forcing member; and spring means held undercompression for constantly urging said forcing member axially inadvanc-v ing direction, said rotating means vbeing capable of operationsimultaneously with lsaid spring means, whereby said forcingfmember willbe axiallyadvanced previous to each said part rotation thereof tothereby successively bring axial and circumferential cam effectsintoplay.

ERNEST DUCHESNE.

